Sol:

Earth's star.  Humans were granted a libary investigation permit for Sol, in connection with their "Sundiver" project, which is still ongoing.
 

Luna:

Earth's only moon, it has no atmosphere and is tide-locked to Earth.   Luna is a large natural satellite, almost making Earth a double planet.  Luna has the oldest Terragen colony.  It was established long before Chimpanzee uplift.   Luna currently hosts most diplomatic missions to the Terragen Confederation, in deference to the fragile nature of Earth's biosphere.
 

Mercury:

A typical close orbit or scorchball planet, this kind of planet is both common and of little interest or use to Galactic Civilisation.  The base of the "Sundiver" project. (Andrew Crystall)
 

Venus:

Second planet of Sol. It is a greenhouse planet.  Because of its inhospitability, a group of free-thinkers and various cultural patriots established a underground colony on Venus during The Bureaucracy.  A long-term terraforming mission started soon thereafter.  This small colony retains its distinct local culture and still consists almost entirely of Humans.  The terraforming project continues --largely with local funds, due to the Venusian emphasis on self-sufficiency.  Roughly one comet a year is directed toward a collision with Venus.  It will be twenty thousand orbits of Sol before the project is complete --ambitious because this is over three times the length of current recorded Human history.
 

Mars:

Fourth planet of Sol.  Mars has a thriving colony and a long-term terraforming project that is proceeding faster than most Galactics would have thought possible given the technology available.  It hosts a substantial Neo-Chimp population.  Mars contributes disproportionately to the Confederation economy.  Mars was the only Terragen settlement to suffer significant loss of life or serious damage to infrastructure during the recent Siege of Earth.  The blockading forces used Mars as their base of operations.  During the Siege the terraforming project was set back many years.  Clan Thennanin now maintains a pre-positioned arms depot and small garrison on Mars.
 

Jupiter:

Jupiter is the largest planet of the solar system with 318 times the mass of Earth.  It is near the maximum possible size for true gas giants.  It emits 66.8+/-8.5% more radiation than absorbed from the sun, the excess being due to gravitational contraction and radioactive decay.  It has a typical gas giant structure with a inner solid core of 10-15 Earth masses.  It rotates with a period of 9 hours 55.5 min.   It has a magnetic field, generated by a conductive core, that is 10 times stronger than the Earth's.  The most noticeable feature of Jupiter is the Great Red Spot.  This is a large persistent storm first observed by Robert Hooke in 586 BxY.  The Terragen Confederation conducts on-going research on Jupiter and all gas giants in Earth system despite protests from H-2 organizations.  (Robert Shaw, Contributing Editor)

Europa:

Europa is the fourth largest of  Jupiter's moons.  Radius 3130 km, density 3.0, surface albedo 90 per_128 (70 percent).  Europa is mostly rock covered in a thin layer of water-ice less than 100 km thick.  The surface is contaminated by sulfur deposits originating from Io.  Europa has almost no impact craters, but is covered by a global pattern of ridges and troughs with a morphology similar to that observed in sea-ice on Earth.  It has very little vertical relief (under 200m).  Simulations indicate that Europa's ocean was initially melted by radioactive heating from its core, and has been kept liquid due to tidal heating.  (Note that tidal heating would not have been enough to melt ice).

Pre-contact Terragen planetologists speculated that life might exist on Europa based on geothermal energy sources
analogous to biological communities that form around Terran ocean vents.  Subsequent investigations have discovered simple multicellular life forms in the oceans comparable to algal mats or sponges.  Europan ecologies (that is, worlds with a global ice-covered ocean) generally have a much lower energy supply than standard organic biospheres get from their suns.  This means Europan biospheres are species-poor with few complex animals.  There is no record of upliftable species having been found on Europan worlds.  (Robert Shaw, Contributing Editor)

Callisto:

The biosphere on this moon is in decline, and seems to be caught in cycles of the type usually associated with far more sophisticated species.  However, no permermant damage seems to be done by these cycles.  This low diversity has, however, made this a little-studied moon.  (Andrew Crystall)

Io:

This volcanically active moon is subject to extreme tidal forces from Jupiter, and is quite a rare phenonema.  However, it is hardly unknown.   The extremely hazardous conditions on the surface, and the fact that it is within Jupiter's intense magnetic field prevent this moon from ever being put to practical use.  (Andrew Crystall)

Saturn:

Although far smaller than Jupiter, being a third of Jupiter's weight and with slightly under half the gravity and density, it is the more studied of the two gas giants.  Saturn's rings are often mined by spaceships in the vicinity for water-ice.  (Andrew Crystall)

Titan:

Although this large moon does not seem to have a biosphere, it is the site of a small independent Human research colony, who are working with several other races to further the Humans' expertise in biological engineering. (Andrew Crystall)

Iapetus:

This moon has an unusual composition, with half the moon being ice covered, and the other half being covered in an unusual rock with certain psi-active properties.  This rock is disturbing to empathic and telepathic individuals.  It also has the uncommon property of almost zero light reflection.  (Andrew Crystall)

Neptune:

Triton:

This volcanically active moon is thought to be a planetoid captured by Neptune's gravity rather than a 'natural' part of the solar system.  Analysis on the metal core of the planet seems to confirm this.  Its surface temperature is very low for a moon-sized body, being just 38 Kelvin. (Andrew Crystall)

Uranus:

This planet is currently the subject of several survey missions by the Terragen Confederation. (Andrew Crystall)

 

Pluto:

This is the site of the Terragen Listening Station, a post that exists to warn the system of incomming fleets, a move felt prudent after the Seige of Earth.  It is it also the site of the Terragens Anti-Matter Research Laboratory.  (Andrew Crystall)